Nowadays, sending information using sound waves is a relatively popular application in smart phones. Smart phones can use sound waves to realize information transmission. Thus, they are able to exchange information without the need of starting Bluetooth or consuming any network data. In sending information using sound waves, it is only possible to use the sound waves to transmit short links, wherein a short link generally refers to a character string formed by joining six characters selected from 62 characters as 0-9, a-z and A-Z. Normally, in order to realize transmission of a numerical value such as a bank account number or a mobile phone number using sound waves, the smart phones will transmit the numerical value to a server through a network, and then the numerical value will be mapped to a short link by the server using a Hash algorithm and returned to the smart phone. Only after that, the short link can be transmitted by the smart phone using sound waves, so as to realize sending the information using sound waves.
However, in practice, it is found that if without any networks, the bank account number or the mobile phone number will not be transmitted to the server to be mapped to a short link, and thus the smart phones cannot send any information using sound waves. Therefore, the application of sending information using sound waves has been restricted.